Lapping machine



av. 5, 1946 G. SELLS EIAL LAPPING MACHINE 5 Sheets-Sheet 1 Filed Oct. 26, 1945 INVENTORS KENNETH cv JOHNSON BY LEE BLACK GALE SELLS ATTORNEY NOV. 5, 1946. SELLS HAL v 2,410,752

LAPPING MACHINE Filed Oct. 26, 1945 3 Sheets-Sheet 2 2 INVENTORS GALE SELLS KENNETH c.w JOHNSON -'EE BLACK ATTORNEY Nov; 5, 1946.

G. SELLS ET AL LAPPING MACHINE Filed 0012. 26, 1945 3 Sheets-Sheet 3 ZNV EN TOR.

GALE SELLS KENNETH c. JOHNSON 7 LEE BLACK Patented Nov. 5, 1946 2,410,752 F I C E LAPPING MACHINE Gale Sells, Kenneth C. Johnson, and Lee Black, Portland. Oregm, assignors to G. G. Campbell and B. H. Stroback, doing business as Radio Specialty Manni'acturing Company, Portsmouth, Oreg.

Application October 26, 1945, Serial No. 624,650

Claims.

This invention relates to lapping machines and is particularly adapted for the lapping of radio crystals, lenses and the like.

The primary object of the invention is to move the objects being lapped between two lapping surfaces by a carrier sheet, said carrier sheet being supported by a carrier ring or frame completely around its outer periphery.

A further object of the invention is to place the carrier sheet under a tension within a carrier ring so that the carrier sheet will not buckle or wrinkle while moving the objects to be lapped between lapping surfaces.

A still further object of the invention is to provide an eccentric movement of the objects being lapped between two lapping surfaces, this movement being imparted to the carrier sheet by its holding frame, which in turn is moved and supported upon driving units, the lapping surfaces remaining relatively stationary on either side of the carrier sheet while the crystals or objects are being lapped.

Another object of the invention is to provide means for controlling the amount of eccentric movement imparted to the carrier sheet, thereby controlling the movement of the crystals or objects being lapped, which determines their final finished shape or contour.

These and other incidental objects will be apparent in the drawings, specifications and claims.

Referring to the drawings:

Figure 1 is a plan view of our new and improved lapping machine for crystals, lenses and the like, parts broken away for convenience of illustration.

Figure 2 is a detail fragmentary sectional view of parts of the device, taken on line 2--2 of Figure 1.

Figure 3 is a side sectional view taken on line 33 of Figure 1.

Figure 4 is a irontview of the lapping machine, taken on line li of Figure 1.

Figure 5 is a plan view of the carrier frame supporting unit which supports the carrier ring and at the same time moving the carrier ring in the lapping operation.

Figure 6 is an inverted planview of the carrier ring or frame, parts broken away for convenience of illustration.

Figure 7 is an exploded view of the carrier ring, carrier sheet and its associated parts,

Figure 8 is a fragmentary plan view of one of the eccentric supports for supporting the unit illustrated in Figure 5.

In the drawings:

Our new and improved lapping machine consists of a base i having a hollow pedestal 2. extending upwardly therefrom. Threadably mounted withinthepedestal 2 is a movable pedestal: 31which can be. adjusted up and down on its threads 4 and locked in any desired position by 2 the locking nut 5'. Resting on the top of the pedestal 3 is a lapping ring 6' held in-a-central position by the shoulder T forming part of the pedestal 3.

Located degrees apart are revolving supports 8, 9 and Hi, the support H) is rotated by a motor H through reduction gear assemblies l2 and I 3. Keyed to the gear Hi of the reduction gear !3 is a vertical shaft l5, which in turn is keyed to the rotor head I6. The revolving supports 8 and 9 are simply rotatably mounted upon a suitable bearing support IT and are not necessarily driven by their supporting shafts.

Mounted on the upper surfaces of the supports 8, 9 and I0 are cranks l8, These cranks form part of a disk l9 which is mounted within the upwardly extending boss 20, by revolving the disk I9 within the boss 20 the throw of the crank i 8 can be changed, the object of which will be described later.

Mounted to the cranks i8 is a supporting unit or ring 2 l. The ring 2| has outwardly extending bracket arms 22 which are mounted to the cranks l8 by suitable bearings 23. The ring assembly 2 lis caused to move in an eccentric movement by the rotation of the supporting units 8, 9 and ill, the unit I!) driving the whole assembly, the purpose of which willbe later described.

We will now describe the carrier assembly A illustrated in Figures 2, 6 and 7, this assembly consists of a ring 24, having a'ledge 25 formedon its upper side. Stretched under this ledge and completely around the ring is a carrier sheet 26 or disk which is usually but not necessarily made transparent and may vary in thickness depending upon the work to be performed.

Referring to Figure '7 the carrier unit A is as sembled by inverting the ring 24, then dropping the carrier sheet 26 down on-the ledge 25, then the gasket 21, and tensioning ring assembly His next put in place. The locking and tension assembly consists of a ring 28, havin thread segments -29 spaced about its periphery for engaging the thread segments 3% formed within the ring 24. By forming the threads 29and 3B in segments the locking ring 28 may be brought into engagement with the ring '25 instantly, then givena partial turn tightening down against the gasket and carrier disk.

The Carrier is further placed under a tension by the floating ring 35, which has a groove 32 into which the ring 28 nests. The ring 3i is drawn up against the carrier sheet 26 at 33 by the bolts 34 which are threaded within the ring 28' and have springs 35 under their'heads and bearing against the ring 3!, causing a continuous tension between the two rings Hand '3! at the same time .causing'the upper part of the ring 3! at 33 to bind against the :carrier: sheet: 26, cause ing the sameto be stretched throughout itsentire area. The action of the springs as stated above These rollers bear aaginst the shoulder 39 of the ring 3| of the carrier unit centralizing the carrier. After the carrier unit has been put in place upon the rollers 31 and between the rollers 38 of the supporting unit 2|, the crystals 40 are dropped into the openings 4| of the sheet 26 after which the lapping ring 42 is placed directly over the lapping ring 6 and held in place by the guide post 43, which drops into the opening 44 of the lapping-ring 42. The guide post 43 forms part ofthe bracket arm 45, which is rotatably mounted to the pedestal 46, resting on the supporting shoulder 41 and being held in proper alignment with the lapping rings'by the latch 48, which drops-into a suitable notch 49 of the shoulder 41. The latch 48 is pivotally mounted at to the arm 45 and has an operating arm 5| for moving the same. A special lapping compound container 52 is mounted by a suitable-holding bracket 53 directly above the post 43 and has a control valve 54 for allowing the lapping fluid to drop down glrough the post 43 and on to the carrier sheet We will now describe the operation of our lappingrmachine, after the carrier unit has been placed upon the supporting ring 2|, as heretofore described, and the objects to be lapped are catcd within the openings 4| of the carrier sheet, and resting upon the upper surface of the lapping ring Send the lapping ring 42 has been brought into position, the motor or driving unit II is started rotating the supportingunits 8, 9 and I0, causing their cranks Hi to move the supporting ring 2| in an eccentric movement thereby moving the carrier sheet 26 and the objects 40 to be lapped in an eccentric movement between the lapping rings 6 and 42. Q

, In order to employ-the principle of moving the carrier sheet between the lapping rings, which are stationary; this carrier sheet must be stretched tightly within the carrier ring at all times in order to prevent buckling of the sheet, therefore we must employ an automatic tension means to maintain a tension or stretch throughout the carrier sheet, the method of accomplishin this we have described above, but we do not wish to be limited to the above method, as-it is the object of our invention to provide a means of maintaining this tension or stretch at all times to the carrier sheet and supportingthe carrie sheet completely around its periphery and as stated before this is the primary object of our invention.

The amount of eccentric movement imparted to-thecarrier sheet 26 may be adjusted by the resetting of the position of the cranks I 8 by the means above described, wherein the disks l9 are revolved within the bosses 20, their location being adjusted bya suitable scale 55, which insures the proper adjustment of all or the cranks.

In having a carrier sheet with no openings, except where the openings 4| occur, considerably less lapping material is required due to the fact that'said lapping material does'not escape down. through the center of the machine, buthas" to work its way completely over the surfaces of the lapping rings' toward the outer edge of the assembly. The lapping material is prevented from flowing over the edge of the carrier unit A by the ledge 25 of the ring 24, thus providing a pool of lapping material over the upper surface of the carrier sheet 26, thereby requiring a minimum of material.

In the eccentric movement of the carrier ring and due to the fact that the carrier ring floats within the supporting ring 2|, a most desirable result is obtained and further this result is improved due to the fact that the lapping ring 42 is imparted a desirable rotary movement about the post 43, hile the carrier sheet is being moved thereunder by the freedom of movement of the carrier unit A and the lapping ring to move relative to the driving or supporting unit 2| the chances of the units being lapped of following the same route in their movement over the surface of the lapping rings is reduced and a more uniform lapping is the result.

We do not wish to be limited to the specific form of mechanical embodiment as we have shown, as other mechanical equivalents may be substituted still coming within the scope of ou claims.

We claim:

1. A lapping machine including a base, upper and lower lapping rings mounted in substantially fixed relation on the base, rotating supports on the base, a supporting ring underlying the lapping rings and driven'eccentrically by the supports, a tension ring connected to the supporting ring, a carrier sheet formed with openings and extending beyond the lapping rings, the extended portions of the carrier sheet being secured between the supporting ring and tension ring, a floating ring carried by the tension ring and bearing beneath the carrier sheet between the lapping rings and the edge support/of the carrier sheet, said tension ring bearing beneath the carrier sheet adjacent the edge support thereof and adjustable to exert an upward pressure upon the carrier sheet throughout the full circumferential length thereof, to maintain a stretching tension on the carrier sheet when being moved between the lapping rings during the lapping operation, and means for imparting motion to one of the supports to compel a gyratory movement of the carrier sheet and elements secured in the holes therein relative to the lapping rings.

2. A construction as defined in claim 1, wherein the supporting ring and tension ring for gripping the carrier sheet are mounted for threaded cooperation and adjustable in that clamping cooperation.

3. A construction as defined in claim 1, wherein the floating ring is guided on the tension ring and wherein a spring is providedfor permitting a yielding of the floating ring relative to the tensioning ring to maintain a uniform stretch on the carrier sheet.

4. A construction as'defined in claim 1, wherein the floating ring is provided with a fiange'and wherein the supporting ring is provided with rollers to underlie such flange for the support of the floating ring.

5. A construction as defined in claim 1, wherein means are provided for adjusting the gyratory play of the carrier sheet.

GALE SELLS. 1 KENNETH C. JOHNSON.

LEE BLACK. I 

